1. Field of the Invention
The present invention relates to a control system for controlling a plurality of industrial robots, and more particularly a control system for performing a synchronously cooperative operation using the plurality of robots.
2. Description of the Related Art
There has not been provided any practical control system for performing a synchronously cooperative operation using a plurality of robots which are respectively controlled by robot controllers connected with one another by a communication line. In the conventional system for the synchronously cooperative operation of the robots, a changeover between a synchronously cooperative operation and a normal independent operation of the robots is set at the time of constructing the system, and it is necessary to change a basic setting of the system for changing the changeover setting for the synchronous cooperative operation.
A combination of robots to be operated in synchronous cooperation has been fixedly set at the time of system construction. In the case where the system has four robots respectively controlled by four robot controllers connected by communication lines, for example, the conventional system has adopted a method in which all of the four robots are operated in synchronous cooperation by these controllers.
In the practical use, according to content of an operation, there is a case where it is desirable that all of four robots, in the above-described example, operate in synchronous cooperation, a case where it is desirable that each robot operates individually, a case where it is desirable that only two or only three of the four robots operate in synchronous cooperation and the remaining robots operate individually, and further a case where it is desirable that two of the four robots and the remaining two robots respectively operate in synchronous cooperation. However, in the conventional synchronously cooperative operation system, robots to be operated in synchronous cooperation cannot be selected in accordance with the operation to be performed. Such a system is inconvenient in that all the robots are operated either in synchronous cooperation or individually, so that the synchronously cooperative operation of desired robots selected from the robots in accordance with the kind of operation can not be performed.
Furthermore, in the synchronously cooperative operation, an operator of the robots has to pay attention to the motion of the master robot as well as the slave robot since the slave robot operates in accordance with the master robot. However, it is difficult for the operator to recognize the synchronously cooperative operation status of the robots from the motion of the robots.